Banjo



(No Model.)

. E. J. GUBLEY.

BANJO.

N0. 274,915. Patented Apr. 3, 1883.

I III nn llflllllwin/e53 UNITED STATES PATENT OFFICE.

-EDWIN J. OUBLEY, OF RAVENSWOOD, ILLINOIS.

BANJO.

SPECIFICATION forming part of Letters Patent No. 274,915, dated April 3, 1883,

- Application filed October 7, 1882. (No model.)

To allwhom 9t may concern:

Be it known that I, EDWIN J. CUBLEY, a citizen of the United States, residing at Ravenswood, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Metal Shells l'or Banjos, of which the following is a specification.

My invention relates to improvements in.

banjos in which the shell or ring which forms the body of the instrument is made entirely of sheet metal, and to which the straining device is attached upon the outer side thereof; and the objects of my improvement are, first, to strengthen the shell by shaping it so that the strain will come upon the metal in the line of its greatest resistance and to maintain the shape of a true circle; second, to beautify the appearance of the shell by covering from view the internal attachments by which the straining device is fastened upon the outer side, and providing a continuous surface unbroken and with rounded corners, capable of being finely and easily polished; and,-third, to strengthen, increase, purify, and render more melodious the musical tone of the instrument. I attain these objects by the metal shell illustrated in the accompanying drawing, in which the tignre is a perspective view of a section of the shell, showing a section of the membrane thereon and a device for straining it.

A represents the shell; B, the membrane; 0, the straining device. The shell is a cylinder having double or triple walls, D E F representing the walls. It is formed by turning over and drawing or spinning the edges of an ordinary sheet-metal cylinder back upon itself nearly its full length, as shown, yet so as to leave an air-chamber between the walls and forming two or three concentric cylinders separated at all points except at the edge by which they are each attached to the outer wall. The inner walls may overlap each other as far as may be desired. but do not come in contact. The large round corners strengthen the circle and prevent bending or buckling when the head is tightly strained. They also add to the beauty of outline. The inner walls cover from view the fastenings of the straining device and present a continuous surface, which, when placed upon an ordinary polishing-wheel, takes readily a fine finish. The sonorous vibrations of the columns of air partly imprisoned within the hollow shell sweeten and purify the musical tone, and the resonant inner walls, the metal of which is hardened and thinned by the spinning, increase the power of that puritied tone.

I am aware that prior to my invention banjos have been made having shells entirely of metal, also having double concentric walls adjustable upon each other to produce a straining device, also having shells formed partly of wood and lined or covered with metal. I do not therefore claim such a construction, broadly; but

What Ido claim as myinvention, and desire to protect by Letters Patent, is-

A banjo or drum constructed with a metal shell formed in one piece withdouble or triple concentric walls separated by air-spaces, all substantially as shown.

EDWIN J. OUBLEY.

Witnesses:

HENRY B. WILLITS, JOHN 0. NELsoN. 

